The present invention relates generally to cooling systems. More particularly, the present invention relates to cooling systems for regulating the temperature of electronic components. The present invention is particularly, but not exclusively, useful for a cooling system for regulating the temperature of electronic components of a desktop computer.
During normal operation, most electronic devices generate significant amounts of heat. If this heat is not continuously removed, the electronic device may overheat, resulting in damage to the device and/or a reduction in operating performance.
In order to avoid such problems caused by overheating, cooling devices are often used in conjunction with electronic devices.
One such cooling device used in conjunction with electronic devices is a heatsink. In such device, a heatsink is formed from a material, which readily conducts heat. The heatsink is usually placed on top of, and in physical contact with, the electronic device.
One method of increasing the cooling capacity of these heatsinks is by including a plurality of cooling fins that are physically connected to the heatsink. These fins serve to increase the surface area of the heatsink and, thus, maximize the transfer of heat from the heatsink to the ambient air. In this manner, the heatsink draws heat away from the electronic device and transfers the heat to the ambient air.
In order to further enhance the cooling capacity of a heatsink device, an electrically powered blower (an axial fan may serve as the blower) is often mounted within or on top of the heatsink. In operation, the blower forces air to pass over the fins of the heatsink, thus, cooling the fins by enhancing the heat transfer from the fins into the ambient air. As the fins are cooled, heat can be drawn from the electronic device and into the heatsink at a faster rate. The blower typically draws air into the heatsink from the top of the heatsink, passes the air over the fins, and exhausts the air from the heatsink in the vicinity of the bottom of the heatsink. Accordingly, the exhaust air is hotter than the intake air.
There are known devices of this typexe2x80x94see, for example, U.S. Pat. No. 6,152,214 xe2x80x9cCooling device and methodxe2x80x9d. The design of the device comprises an axial fan that produces a flow passing by heat exchanging channels of the heatsink. However, due to the weak airflow in the area adjacent to the axial fan axle, the conditions for cooling of the central part of the heatsink located underneath a hub of the axial fan are unfavorable. In this case non-uniform cooling of the heatsink and electronic device, for example, processor, will take place. Besides, the energy of airflow outgoing from the axial fan impeller in the axial direction is expended because of deceleration and turn in motion before this airflow enters to the heat exchanging channels. This fact decreases the speed of airflow passing by the heat exchanging channels, which, in its turn, doesn""t allow obtaining good conditions for the heat exchange process.
Centrifugal fans are used rarely in the cooling device designs for the purpose of producing airflow.
Specifically, U.S. Pat. No. 5,838,066 xe2x80x9cMiniaturized cooling fan type heatsink for a semiconductor devicexe2x80x9d offers a design employing a centrifugal fan that is installed to the side of the heatsink. In one particular embodiment of this invention the cooling airflow passes by rectilinear heat exchanging channels of the heatsink.
However, placement of centrifugal blower to the side of the heatsink increases device size. This is so because the location of centrifugal blower leads to insufficient coordination between the direction of channel inlets and direction of airflow supplied from the blower. The loss in airflow energy results in the reduction of airflow motion speed in heat exchanging channels and in the decline of heat exchange efficiency. A portion of energy is also expended on friction against the casing, in which the blower is enclosed.
Cross flow fans/blowers are used much more rarely in the cooling device designs for the purpose of producing airflow.
It is known cooling devices that uses cross flow fan (see U.S. Pat. No. 6,047,765 xe2x80x9cCross flow cooling device for semiconductor componentsxe2x80x9d). According to this design air flow producing by cross flow fan where an axle of an impeller is perpendicular to fins of a heatsink.
Another cooling device uses cross flow fan (see U.S. Pat. No. 6,227,286 xe2x80x9cHeat sink and information processor using heat sinkxe2x80x9d, FIGS. 15A-15C and 40A-40C). According to this design an axle of an impeller is perpendicular to a heatsink body.
The use of a cross flow type blower allows for the suction and discharging of air at the sides of the cross flow fan. The airflow through cross flow fan is a plane-parallel flow with respect to a plane perpendicular to the cross flow fan axle. This provides uniform airflow through a heatsink. However, cross flow type blowers require more space, thereby reducing the space used for heat exchange decreasing efficiency of cooling device in total.
Thus, it would be generally desirable to provide an apparatus, which overcomes problems associated with cooler for electronic devices.
Accordingly, it is an object of the present invention to provide apparatus including a heatsink and a blower in a cooler for electronic devices, which is capable of significantly improving heat efficiency thereof.
In order to achieve this object, a cooler for electronic devices is provided with a heatsink and a cross flow blower with an electric motor. The heatsink comprises a base and heat exchanging means. The base provides thermal contact with the electronic device and the heat exchanging means. The cross flow blower comprises a drum type impeller with an axis of rotation substantially normal to the base. The heat exchanging means are located inside and may be further located outside of the drum type impeller. The heatsink further comprises heat-spreading means that provide thermal contact between the base and the heat exchanging means.
The heat exchanging means located inside of the drum type impeller are flat disks substantially perpendicular to the axis of rotation and thermally connected with the base by at least one heat-spreading means located inside of the drum type impeller. This at least one heat-spreading means may be made as heat-pipe. Further, this at least one heat-spreading means may be made as a guide vane.
The heat exchanging means located outside of the drum type impeller are, illustratively, fins substantially perpendicular to the base. According to second embodiment of the present invention, the heat exchanging means located outside of said drum type impeller are flat plates substantially perpendicular to the axis of rotation and thermally connected with the base by at least one heat-spreading means located also outside of said drum type impeller. This at least one heat-spreading means may be made as heat-pipe.